The present disclosure relates to a multilayer ceramic capacitor and a board having the same mounted thereon.
A multilayer ceramic capacitor, or a multilayer chip electronic component, may be a chip-shaped condenser, which is mounted on boards of various electronic products such as display devices, liquid crystal displays (LCDs), plasma display panels (PDPs) and the like, for example, as well as computers, personal digital assistants (PDA), mobile phones, and the like, to serve to charge or discharge electricity therein or therefrom.
Since such a multilayer ceramic capacitor (MLCC) has advantages such as a small size, a high capacitance, ease of mounting, or the like, such a multilayer ceramic capacitor may be used as a component in various electronic devices.
The multilayer ceramic capacitor may include a plurality of dielectric layers and internal electrodes alternately stacked between the dielectric layers and having different polarities.
Since the dielectric layer has piezoelectric and electrostrictive properties, a piezoelectric phenomenon occurs between the internal electrodes due to vibrations generated when a direct current (DC) or alternating current (AC) voltage is applied to the multilayer ceramic capacitor.
These vibrations may be transferred to a board on which the multilayer ceramic capacitor is mounted through external electrodes of the multilayer ceramic capacitor, so that the entirety of the board serves as a sound radiating surface to generate a vibration sound, noise.
The vibration sound may be within an audio frequency range of 20 to 20,000 Hz, which may cause listener discomfort and is referred to as an acoustic noise.
Recently, a degree of the acoustic noise has become an important factor in determining quality of the multilayer ceramic capacitor.
In accordance with an increase in capacitance of the multilayer ceramic capacitor, a mechanical deformation amount of dielectrics may be inevitably increased. Therefore, various methods for solving this problem have been attempted.
One of the methods is to control an acoustic noise by controlling an amount of solder used to bond the multilayer ceramic capacitor to the board.
However, in this method, bonding strength between the board and the multilayer ceramic capacitor is decreased in proportion to an amount of the solder. Thus, it is difficult to expect a large decrease in the acoustic noise even in a case in which an amount of the solder is decreased.
Another method is changing an internal structure of the multilayer ceramic capacitor.
However, the method of changing an internal structure of the multilayer ceramic capacitor generally requires a size or a form of a product to be mainly changed. Thus, an additional appropriate method of mounting the multilayer ceramic capacitor needs to be introduced.
Still another method is controlling a direction in which the multilayer ceramic capacitor is mounted.
However, the method of controlling a direction in which the multilayer ceramic capacitor is mounted requires a separate process to separately align the direction in which the multilayer ceramic capacitor is mounted.